21654267181853 has 2 divisors, whose sum is σ = 21654267181854. Its totient is φ = 21654267181852.

The previous prime is 21654267181847. The next prime is 21654267181873. The reversal of 21654267181853 is 35818176245612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21235479590809 + 418787591044 = 4608197^2 + 647138^2 .

It is a cyclic number.

It is not a de Polignac number, because 21654267181853 - 2²² = 21654262987549 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21654267181792 and 21654267181801.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21654267181873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10827133590926 + 10827133590927.

It is an arithmetic number, because the mean of its divisors is an integer number (10827133590927).

Almost surely, 2^{21654267181853} is an apocalyptic number.

It is an amenable number.

21654267181853 is a deficient number, since it is larger than the sum of its proper divisors (1).

21654267181853 is an equidigital number, since it uses as much as digits as its factorization.

21654267181853 is an evil number, because the sum of its binary digits is even.

The product of its digits is 19353600, while the sum is 59.

The spelling of 21654267181853 in words is "twenty-one trillion, six hundred fifty-four billion, two hundred sixty-seven million, one hundred eighty-one thousand, eight hundred fifty-three".